东方1-1海管悬跨分布特征及治理效果分析

海底管道对海上油气田安全生产有着非常重要的作用,对东方1-1海管进行了连续6年的无人有缆遥控水下机器人(remote operatedvehicle,ROV)调查,根据调查数据,分析了海管悬跨的分布特征以及变化情况,按海管悬跨严重程度进行了风险等级分区。结果表明在受水动力影响最大的深水平坦区海管悬跨分布密集,并有逐年加剧趋势,安全风险较大。并对悬跨形成机理和极限悬跨长度进行了分析和阐述。介绍了沙袋支撑和局部抛石填埋悬跨治理方法的原理和优缺点,对比分析了治理效果情况,认为局部抛石治理方法效果优于沙袋治理。

Analysis of DF1-1 subsea pipeline free-span distribution characteristics and rectification effects

Subsea pipelines play an essential role in the safety of offshore oil and gas fields. Remotely operated vehicle (ROV) surveys of the Dongfang 1-1 subsea pipeline have been routinely conducted for more than six years. Based on the several years ROV survey data, the distribution characteristics and changes in the pipeline free spans were analyzed, and pipeline was partitioned according to the severity and risk levels of its free spans. The analysis results show that in deep water areas where the influence of hydrodynamic forces is greatest, free spans are densely distributed and there is an annual increasing trend of high safety risk. The mechanism and maximum length of the free span are analyzed and calculated. Based on the ROV survey data, we also introduce the principles, advantages, and disadvantages of free-span rectification by sandbagging and partial gravel dumping and analyze their free-span correction and rectification effects. The results indicate that the effect of partial gravel dumping is better than that of sandbagging.